a) Field of the Invention
The present invention relates to an improved method for removing and collecting plating wax removed from waxed components and to an improved device for reducing said method to practice. Examples of such components are turbine engines components from aircraft, which are partially coated with wax before being plated with a specific metal to ensure that only non-coated areas be plated.
b) Brief Description of the Prior Art
The traditional method for removing the wax from these components comprises the steps of immersing fully the waxed component for 5 to 20 min. in a mechanically heated wax remover solution such as D-SOLV WAX DESOLVER(trademark) (commercialized by Mag-Chem Inc.). After that period, the components are put in a mechanically agitated hot water (60-100xc2x0 C.) for 1 to 5 min. The major drawbacks with such a method are that it is expensive and not environmentally friendly. Enormous amount of expensive wax remover solutions are necessary since the remover became rapidly saturated with wax and must then be discarded. It is also impossible to recover the wax removed from the component.
To solve the problem, the Applicant (Mag-Chem Inc.) has developed a technologically advanced method for collecting in one simple step over 95% of plating wax before the component reaches the costly dissolving bath stage. This method comprises the steps of:
a) immersing the waxed component in a bath of heated liquid masking wax;
b) bathing the waxed masked component in an automatic wax collecting equipment (commercialized by Mag-Chem Inc. under the brand name AWC SYSTEM(trademark)) filled with a heated wax remover (85-95xc2x0 C.) such as KEMSOL 606(trademark);
c) fully immersing the component for 5 to 20 min. into a mechanically heated wax remover solution such as D-SOLV WAX DESOLVER(trademark) (commercialized by Mag-Chem Inc.); and
d) immersing the component into mechanically agitated hot water (60-100xc2x0 C.) for 1 to 5 min.
According to factors such as the type and size of the component and the quantity of wax coating it, it may be necessary to perform the supplementary step of:
e) immersing the component in a 10% solution of a wax remover solution such as SOLUWAX(trademark) heated at 71-77xc2x0 C. for 10 to 15 min.
The last step of the method consists of:
f) immersing the component in hot water (60-100xc2x0 C.) for a final rinse.
This method has many advantages. The hot wax immersion step a) removes most of the plating wax and leaves a thin uniform film of wax on the component. In step b) up to 95% of the remaining wax is collected. This method is thus economical and environmentally superior since 1) it increases the wax remover solutions lifetime and 2) the collected wax may be re-used or sold.
As stated above, this advanced method uses an automatic wax collecting equipment named AWC SYSTEM(trademark). The method carried out within this equipment comprises the steps of:
a) fully immersing the waxed component in a process tank filled with a heated wax remover solution and whereby the wax is removed from the component and floats on top of the remover solution;
b) letting the wax remover solution and wax floating on top of it overflow into a wax separator tank that is operatively connected to the process tank to a predetermined first level;
c) letting the floating wax decant within the wax separator tank on top of the wax remover solution and overflow when it has piled up at a predetermined second level lower that the first level;
d) pumping the wax remover solution from the wax separator tank back to the process tank with a circulating pump so as to maintain within the process tank a level of wax remover solution sufficient to allow step b) to be carried out;
e) recovering into a container the decanted wax having overflowed from the wax separator tank.
Although very effective, this method is not fully automatic. The wax remover is volatile at the high temperature used (85-95xc2x0 C.) and continuously evaporates. As a result, after a certain period of time, the wax separator tank is entirely filled with decanted wax. The process must then be temporarily stopped in order to allow maintenance personnel to manually fill the separator tank with a new batch of wax remover in order to avoid pumping of decanted wax to the process tank. This level adjustment is a loss of time and results in a loss of productivity.
To improve this method, the Applicant proposes to continuously monitor and automatically control the level of wax remover solution in the separator tank. Although it may seem simple, it is not easy to determine the level of wax remover solution which is found under the wax layer. Both remover and wax are organic compounds which are non-electrically conductive. Accordingly, usual electric level controller using electrodes cannot be used with such a collector. Furthermore, since the wax layer is floating above the wax remover solution, conventional controller using float like device may not be used either. It is further impossible to use optical device (laser-like) since the floating wax layer is not translucent.
In accordance with the present invention, the Applicant has discovered that it is possible to continuously monitor the level of wax remover solution which is present under the wax layer by using a measurement device operating with microwaves. Examples of such devices are described in U.S. Pat. Nos. 5,594,449; 5,614,911; 5,659,321 and 5,689,265; and in Canadian patent application No. 2,215,626. However, these devices have never been used in the avionic industry.
Therefore, the present invention provides an improved wax collecting method and a fully automatic device for reducing to practice this method, wherein the level of wax remover solution in the separator tank is continuously monitored and automatically maintained to a preset level thanks to a level controller operating with microwaves.
It is an object of the present invention to provide an improved collector for removing and collecting a plating wax from a waxed component, the collector comprising:
a process tank filled with a heated wax remover solution into which the waxed component is fully immersed and whereby the wax is removed from the component and floats on top of the remover solution, the wax remover solution and wax floating on top of it overflowing to a predetermined first level;
a wax separator tank adjacent and operatively connected to the process tank for receiving the overflow of remover solution and floating wax, the floating wax decanting therein and forming a decanted wax layer floating above a level of wax remover solution lower than the first level, the decanted wax layer overflowing once it has piled up to a predetermined second level lower than the first level;
a circulating pump operatively connected to the process tank and the wax separator tank for pumping the wax remover solution from the wax separator tank back to the process tank;
a level controller operating with microwaves, the level controller being operatively connected to the wax separator tank for monitoring the level of remover solution below the decanted wax layer, the level controller comparing the level of remover solution with a preset level lower than the second level;
a chemical pump operatively connected to a reservoir of supplemental wax remover solution and to the wax separator tank and/or to the process tank, the chemical pump being further operatively connected to and controlled by the level controller in order to maintain the level of wax remover solution close to the preset level; and
an optional container operatively connected to the wax separator tank for recovering the decanted wax overflowing from the wax separator tank.
It is also an object of the present invention to provide a method for removing a plating wax from a waxed component, the method comprising the steps of:
a) fully immersing the waxed component in a process tank filled with a heated wax remover solution and whereby the wax is removed from the component and floats on top of the remover solution;
b) letting the wax remover solution and wax floating on top of it overflow into a wax separator tank that is operatively connected to the process tank to a predetermined first level;
c) letting the floating wax decant within the wax separator tank to form a wax layer floating on top of the wax remover solution and letting this layer overflows when it has piled up to a predetermined second level lower that the first level;
d) pumping the wax remover solution from the wax separator tank back to the process tank with a circulating pump so as to maintain within the process tank a level of wax remover solution that is sufficient to allow step b) to be carried out;
e) monitoring and controlling a level of wax remover solution that is present in the wax separator tank by using a level controller operating with microwaves, the level controller comparing the level of wax remover solution below the layer of decanted wax with a preset level lower than the second level;
f) supplying with a chemical pump a supplement amount of wax remover solution stored in a reservoir into the wax separator tank and/or the process tank, the chemical pump being operatively connected to and controlled by the level controller in order to maintain the level of wax remover solution within the wax separator tank close to said preset level; and
g) optionally recovering into a container operatively connected to said wax separator tank the decanted wax overflowing from the wax separator tank.
The invention and its numerous advantages will be better understood upon reading the following non-restrictive description of a preferred embodiment of it, made with reference to the accompanying drawings.